In general, when a current flows through a semiconductor element or a peripheral circuit, an electric field and a magnetic field are induced around the current to generate unnecessary electromagnetic noise. The unnecessary electromagnetic noise influences the operation of other circuits, elements, etc. As an example, there is a case where electromagnetic noise emitted from a semiconductor device mounted in mobile communication equipment such as a cellular phone is incident on the antenna to cause an interference with radio wave reception.
To shield such electromagnetic noise and protect the semiconductor element, there is a method in which a shield plate covering a circuit module is provided. However, the method in which the circuit module is covered with the shield plate may have difficulty in the downsizing of the circuit module.
In contrast, there is a semiconductor device (semiconductor package) in which a shield film is formed on the outer periphery of a semiconductor element itself. By installing such a semiconductor device in a circuit module, the circuit module can be downsized. Higher speed operation is required for the semiconductor element, and a highly reliable semiconductor device that shields electromagnetic noise more is desired.